Flotation of minerals



UNITED STATES PATENT OFFICE.

RALPH E. SAYRE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR '10 METALS RECOVERY COMPANY, 01 NEW YORK, N. Y., A CORPORATION OF MAINE.

ILO'IA'IION OF MINERALS.

llo Drawing.

To all whom it may concern.

Be it known that I, RALPH E. Serum, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny, State of Pennsylvania, have invented certain new and useful Improvements in the Flotat1on of Minerals; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which 1t appertains to make and use the same.

This invention relates to the concentration of minerals, such as sulfid ores and the like, by flotation.

The invention is based upon the discovery that the flotation o eration can, in many cases, be improved y the addition to the ore or mineral pulp of a thio-aldehyde compound, such as is produced, for example, by passing hydrogen sulfid into aqueous acetaldehyde or paraldehyde made strongly acid with hydrochloric acid. Such thioaldehyde compounds have a marked sel'ec-' tive or collecting or mineral-modifying action, and materially promote the flotation of the mineral.

The thio-aldehyde compounds can be produced in any suitable manner, for example, from acetaldehyde or paraldehyde by passing hydrogen sulfid into a strongly acid aqueous mixture. The resulting solid mass of crystals can be recrystalized, or used directly without further crystallization.

The thio-aldehyde compound can be incorporated with the ore or mineral pulp in any suitable manner which will insure ItS uniform incorporation and dissemination throughout the ulp. It may thus be incorporated by a ding to the grinding mill, in which the ore is ground, or it can be first dissolved in a solvent, and added in the form of the resulting solution, for example, in anilin. The flotation operation can be carried out in any suitable apparatus, such as an ordinary Callow cell, or in apparatus where the air is incorporated in the ore pulp by mechanical agitation.

It is of advantage in many cases, as with certain copper ores, to add to the ore pulp a small amount of alkali, which may be suflioient in amount to give to the ore pulp a distinct alkaline reaction. When alkalis are used, it is desirable to give them an appreciable time of contact with the ore pulp before suhmcting the latter to flotation.

Specification of Letters Patent.

The alkalis can thus be added with advan- Patented Mar. 1, 1921.

Application filed July 2, 1920. Serial No. 393,608.

tage in the grinding mill so that they will be present during the grinding operation.

The alkali maybe caustic alkali, such as sodium hydrate, or an alkaline salt, such as sodium carbonate, or even lime or calcium oxld or hydrate can be used.

The amount of the thio-aldehyde compound added can vary somewhat, and may be as little as one-half pound per ton of ore, that is, calculated on the weight of the ore and not of the ore pulp. Larger amounts may, however, be used, as well as even smaller amounts in some cases.

I The invention will be further illustrated by the following specific examples of tests made upon a copper sulfid ore:

Example 1 :500 parts by weight of Utah Copper Qompanys ore was ground in a pebble m ll with 250 parts of water, caustic soda equivalent to two pounds per ton of dry ore, and thio-aldehyde compound equivalent to one-half pound per ton. The ground pulp was diluted and subjected to flotatlonin a Callow rougher cell. Aeration of the pulp was continued until the concentration of the sulfid mineral practically ceased. A satisfactory concentrate and high recovery were obtained.

Example 2 :-The treatment was similar to that of example 1 except that the thio-aldehyde compound was dissolved in anilin in amount equivalent to about one pound per ton, and the resultin solution was added to the ore pulp in the (/allow cell.

\Vhile the thio-aldehyde compounds pose sess frothing qualities, the amount of froth produced, using the small amounts of thioaldehyde compound above referred to, may be insuflicient for satisfactory flotation. Instead of increasing the amount of thio-aldehyde compound, this action can be supplemented by the addition of a small amount of a flotation agent having good frothing qualities, and which will cooperate with the thio-aldehyde compound in giving the desired frothing, as well as the selective or collecting, properties. Among such agents, having good frothing qualities may be mentioned terpineol, pine oil, etc. The thioaldehyde compounds may thus be used in conjunction with flotation agents which themselves have both frothing and collecting properties, for example, with many of the common flotation oils, etc.

I claim:

1. The method of effecting the concentration of minerals by flotation, Which comprises adding to the mineral pulp a small amount of a thio-aldehyde compound, and subjecting the resulting mixture to a flotation-o eration; substantially as described.

2. he method of effecting the concentration of minerals by flotation, which comprises adding to the mineral pulp a small amount of a selective or collecting or mineral-modifying agent, deficient in frothing qualities, together with a small'amount of a thio-aldehyde compound, and subjecting the resulting mixture to a flotation operation; substantially as described.

3. The method of effecting the concentration of copper sulfid ores by flotation, which comprises addin to the mineral pulp a small amount 0 an alkali and a small amount of a thio-aldehyde compound, and subjecting the resulting mixture to a flotation operation; substantially as described.

4. The method of effecting the concentration of copper sulfid ores by flotation, which comprises adding to the mineral pulp a small amount of an alkali, a small amount of a flotation agent deficient in frothing properties, and a small amount of a thioaldehyde compound, and subjecting the resulting mixture to a flotation operation; substantially as described.

In testimony whereof I afiix my si ature.

RALPH E. SA RE. 

